In a control device that outputs a driving signal to a fuel injector, it is required that a variation of a fuel injection quantity is decreased and an exhaust emission and a drive ability is improved. According to Patent Literature 1, an injection quantity variation caused by a lifting quantity variation in a partial-lifting region of the fuel injector is corrected with a precision, and an injection quantity control precision in the partial-lifting region is improved. Specifically, a valve-closing position of the fuel injector is detected. Patent Literature 2 discloses a driving device having an object to surely detect an operation timing of a valve body with a high precision.